Ratchet mechanism.



PATENTED JULY 5, 1904.

A. SPANGBNBERG. RATGHET MECHANISM.

APPLICATION FILED APR. 4, 1904.

N0 MODEL.

Inventor W. 55, Attorney Witnesses UNIT D i STATES Patented July 5,1904.

PATENT OFFICE.

NILES-BEMENT-PON D ()OMPAN Y,

OF JERSEY CITY, NEWV JERSEY.

RATCHET MECHANISM.

SPECIFICATION forming part of Letters Patent No. 764,311, dated July 5,1904;.

Application filed April 4, 1904.

1'0 (ZZZ whom it may concern.-

- Be it known that I, ALFRED SPANGENBERG, a citizen of theUnited States,residing at Plainfield, Union county, New Jersey, (post-office address,No. 826 West Sixth street, Plainfield, New J ersey,) have inventedcertain new and useful Improvements in Ratchet Mechanism, of which'thefollowing is a specification.

There is a class of ratchet mechanism employed in transmitting rotarymotion from a driver to a driven member where the driver makes anindefinite number of turns in alternating direction and in which thedriven member is to make a definite number of turns. Such devices areoften used on metal-planing machines where the driver is represented byan element turning in alternative directions and to a varying extentdependent on the length of table-stroke being immediately dealt with andin which the driven member is a feed part moved a definite degree ateach table-stroke.

My present invention embodies very substantial improvements upon knowndevices of very much similar general construction.

My present invention will be readily understood from the followingdescription,- taken in connection with the accompanying drawings, inwhich- Figure 1 is a front elevation of a ratchet mechanism employing mypresent improvements; Fig. 2, a substantially horizontal section of thesame in the plane of line a viewed from below, and Fig. 3 a verticalsection in the plane of line b viewed from the front.

In the drawings, 1 indicates a fixed housing illustrated as in mereplate form, which housing may .well serve as the backfor a casing tocontain the mechanism, its outline being immaterial, the rectangularform being illustrated, mainly, for the purpose of suggesting to the eyethe non-rotary character of this part; 2, a hollow shaft journaled inthe housing and constituting the driven member of the mechanism; 3, adisk fast on this shaft; 4, a double-ended pivot-pawl carried by thisdisk; 5, a brake engaging the disk and serving to prevent erraticmovements of the disk under certain conditions, this brake not beingneeded in all cases; 6, a shaft concentrically mounted Serial No.201,492. (No model.)

in the hollow shaft 2 and forming the driver 5 .of the system; 7, aratchet fast on this driving-shaft and having its teeth facing in bothdirections appropriate tocooperation with the opposite ends of the pawlalternatively; 8, a clutch-ringfrictionally carried by the ratchet,

this ring being illustrated as a gap-ring springexpanded with a facialrecess in the ratchet; 1 9, an arm projecting inwardly from the pawl,and carrying a pin engaging the clutch-ring in such mannerthat if theclutch-ring shift angularly relative to the pawl it will rock the 1pawl; 10,-a pair of fixed cams in the path of Ethe pawl and adapted whenengaged by the f pawl to tip the pawl out of engagement with theratchet, all of the parts thus far referred 5 @to being generallyconsidered of usual construction and arrangement; 11, a pair of. sujpercams pivoted on the fronts of fixed cams 10' and cooperating with thelatter upon the 5 pawl, these movable cams having faces pro- 7 jectingat points inwardly beyond the faces of 1 the fixedcams; 12, a pinprojecting from the ;rear face ofeach supercam into a substantiallyradial .slot inthe fixed cam to permit of but limit the movement ofthesupercams relative to the fixed cams; 13, a'spring carried by eachfixed cam and pressing inwardly upon the pin 12 to urge the supercam tonormal inward position; 14, a spring for expanding the clutch-ring; 15,a fixed outward projection from the housing toward the back ofpawl-carrying disk 3; -16, 'b'ulfers or stops, preferably of .fiber,dovetailed into the angular faces of the projection 15, and 17 .a,stoplug carried by the back of pawl-carryingdisk 5 3 in position to haveits opposite angular faces cooperate alternately with the two buffers16.

Driving-shaft 6, with its ratchet, is to make an indefinite number ofturns, first in one di- 9 rection and then in the other. Driven shaft 2is to make a partial turn of constant extent, first in one direction andthen the other. In

short, as the driving-shaft 6 reverses its direction of motion thedriven shaft 2 is to accompany it inits rotation through a definiteportion of a turn and then come to rest.

In Fig. 3 the angular distance swept through by stop-lug 17 on the disk3 measures the defi nite degree of rotation of the driven shaft, theangular faces of the stop-lug striking first'one and then the otherbuffer, the buffers serving to effect a sufficiently definite arrestwithout involving an undesirable amount of noise or rebound.

In Fig. lassume the ratchetturning in the direction indicated by thearrow. It is driving the driven shaft in the same direction through themedium of the pawl. Assume supercams 11 to be absent. In course of timethe advance extremity of the pawl engages the right-hand one of fixedcams 10, with the result that the pawl is tipped out of engagement withthe ratchet, whereupon the driven shaft comes to rest, .thedriving-ratchet continuing.

on. This enforced tippingof the pawl is. opposed by clutch-.ringB,whosetendency is to urge the pawl again to the ratchet. If. the rotarymotionof the parts be slow, then the driven member will. come to. restthe instant the cam or the pawl orthe teeth become worn, and at theseslow speeds the release may take place before the driven member reachesits stop, and it is manifest that breakage will occur if the releasetakes place after the buffer has been engaged. If the parts turn at highspeed,.then after the release of the pawl momentum may carry the drivenparts to the buffer-point, but rebound therefrom may carry the pawl farenough back on the cam to cause the pawl to make contact with the tipsof the teeth. Such has been the unsatisfactory action of devices of thisconstruction in the absence of the supercams.

Now in the present construction the supercams are held to workingposition by springs strong enough to tip the idle pawl against theresistance of the clutchsring 8, bu t not strong enough to release thepawl from working engagement with the ratchet-tooth. The result is thatthe supercam becomes pushed outwardly, and the fixed cam does the workof releasing the pawl from the tooth, the actual release taking place atas sharply a defined point as may be and the supercam then movinginwardly and completing the tipping of the pawl to the neutral position,quite out of danger of any possible contact with the teeth. This actionmay. be relied upon no matter how slowly the parts turn. In the olderarrangements the brake 5 was required to do somewhat heavy work, costingpower and increasing the wear on all parts, as its resistance wasrequisite to insure proper action. In the present construction the brakeneed act but Furthermore, the time of release aseffected by the cam issub ect to variations as lightly in any case and for slow motions is notnecessary. at: all, .as' supercams will keep the pawl "from againengaging the ratchet.

The reversal takes place in an obvious manner, the first effect of thereversal of the direction of motion of the ratchet-wheel being throughthemediumofthe clutch-ring to tip the pawl from the neutral. intoappropriate engagement with the ratchet, whereupon the driven memberaccompanies the driver till the pawlis released by the second cam. Intheolder constructions the clutch-ring was required to work rathervtightly, as it. was liable to have to deal with apawl tipped only to theclearing angle, while in the present construction the supercams insurethe tipping of the pawl to the netural position, and'the clutchring. hasa comparatively lightduty. to perform,., the general. result being.-amore posis tive working,- a. superior. freedom from. the

lost work of friction, .and 5a greatly increased durabilityofthe parts.In the older constructions much. annoyance has been-experienced from,the wearing of thepoi-nts of the teeth and pawl; Again, in theolderconstructions it was necessary that'thepawl engage the teeth at aneasily-releasing angle of contact, while in the present construction theangle of gheltooth-faces may. be much more nearly ra- I claimias myinvention- 1. In a ratchet mechanism,.the combination, substantially asset forth,.of a rotary driver having a double-faced-ratchet, a rotarydriven member carrying a double-endedpivoted pawl, a friction devicecarried by the driver and tendingto tip the pawlin position to cause thedriven member to turn with the driver, apair of fixed cams inthe-path-of the pawl to-engage the pawl'and ti-p it out of engagementwith the ratchet, and a: springpressed supercam on each fixed-camadaptedto tip the pawlto neutral position-after the fixed cam has released itfrom the ratchetwheel or while it is so releasing it.

2. In a ratchet mechanism, the combina tion, substantially as setforth,.of a rotary driver having adouble-faced ratchet, a rotary drivenmember carrying adouble-ended pivoted pawl, a friction device carried.by the driver and tendingto tip the pawl in position to cause the drivenmember to turn with the driver, a pair of fixed cams in the path of thepawl to engage the pawland tip it out of enengagement with the ratchet,a stop-lugcarried by the driven member, a fixed stop presenting twoangularsfaces in the path of said stop-lug, and buffers dovetailed intothe faces of the fixed-stop.

ALFRED SPANGENBERG.

Witnesses:

J. T. M. MURRAY,. A, G. STEBBINs.

